Radon and radium in lake-bottoms can find drill targets, a powerful method of uranium exploration under lakes.
Radon and radium geochemistry of lake-bottom water and sediment is a detailed exploration tool in the
Athabasca Sandstone and other areas where giant uranium deposits are found under lakes.
Gamma radiation is blocked by water, and under-lake uranium ore bodies and radioactive
boulder trains cannot be detected by airborne or ground gamma-ray scintillometer or spectrometer surveys.
The Midwest Lake uranium deposit is under the lake and was found by drilling up-ice from a radioactive boulder train.
When we sampled the surface water around the edge of Midwest Lake we found that
the arm of the lake overlying the eventual discovery was anomalous in radon.
It is likely that our radon anomaly is due either to the
extension of the boulder train under the lake, or to broken up and weathered portions
of the orebody on the lake bottom.
Had we run a grid over that arm of the lake, collected water samples near the bottom, and
analysed them for radon, it is likely we would have defined a much smaller target suitable
- Collecting sediments and analysing for radium (or radon) would have refined the target even further.
There is some
evidence that uranium, being more soluble, is more readily leached from sediments,
leaving an anomaly in radium but not un uranium.
Movement of radon is limited by its 3.8-day half-life and its high solubility in water.
no radon bubbles, and below the water table there is no mobile gas phase to scrub out and
transport the radon.
Precursors of radon in the uranium decay series, including radium with its 1622-year half-life, might be expected to diffuse farther than radon.
Equilibrium in the radium-radon pair occurs quickly with a half-life of 3.8 days,
so that a radium anomaly is soon reflected by a radon anomaly.
Uranium, on the other hand, takes a million years to grow into equilibrium with its daughter radon.
Once radon gets into the lake water it will not move into the sediments.
It will not get trapped by clays or organics or get precipitated.
With our instruments, radon and radium analyses are available immediately in the field.
Radon must be done within a week; radium can be done any time.
If chunks of ore and coarse sand are releasing radon into the water, then sampling fine
sediments (like organics and clay) might miss the anomaly!
We should also collect bottom water samples and analyse them for radon.
Robert H. Morse, Ph.D., P.Eng.
October 30, 2009
We measure: radon - radium - thoron - radon daughters - alpha radiation.
is recognized as the most sensitive and reliable method for these elements.
Our instruments are used around the world in exploration for uranium, oil & gas, groundwater and hydrothermal,
and in environmental protection, health physics, earthquake prediction, and evaluation of hydrocarbon and NAPL contamination.
In the radon business since 1968, our latest major instrument update was 2015.
Modern, low-power, field-rugged electronics. Some earlier versions still working after 35 years.
Continuous real-time monitoring and data recording.
Winter and summer, from the Sahara Desert to the Canadian Shield, our instruments have faced up to severe field conditions.
- Intrinsically safe functions.
Sensitive to geochemical trace levels necessary for radon in lake water and for radon-thoron isotope ratios.
Can work in a tent without electricity or be carried from point to point in the field.
50 readings per day. Results available immediately.
Rechargeable battery pack good for a long day in the field and recharges in a few hours.
Can be operated by junior personnel if carefully supervised.
Same instruments used for radon and radium in soil, sediment,
plant parts, rocks, water, soil gas, air, and snow, and for radon daughters in air.
- EPA compliant.
Click here for more details of instruments.
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accessories we provide
Technical specification sheets and pictures of our instruments provided on request.
Multilingual consulting and training (if required).
For instruments contact|
R.H. Morse & Associates Ltd.